Director firing system



April 22, 1930. E. A. SPERRY ET AL 7 1,755,340 DIRECTOR FIRING SYSTEM IOriginal Filed April 9, 1917 6 Sheets-Shee 1 flay IN VEN TOR6 TTORNEY.

April 221930. SPERRY ET AL I 1,755,340

' DIRECTOR FIRING SYSTEM Original Filed April 9, 1917 5 sh t s 2 74 5INVENTORS April 22, 1930. E, A, SPERRY ET AL 1,755,340

DIRECTOR FIRING SYSTEM I Original Filed April 9, 1917 6 Sheets-Sheet. 3

INVENTORS N BY ' TTORNE April 22, 1930; E. A. SPERRY ETlAL DIRECTORFIRING SYSTEM I 6 Sheets-Sheet 4 Original Filed April 9, 1917' INVENTORSApril 22, 1930. E. A. SPERRY ET AL 1,755,340

DIRECTOR FIRING SYSTEM Original Filed April 9, 1917 a Sheets-Sheet 5 wigM A'TTORNEY,

April 22, 1930. SPERRY ET AL 1,755,340

DIRECTOR FIRING SYSTEM Original Filed April 9, 1917 6 Sheets-Sheet 6INVENTORS [2mm 19 5PRRY & flENE/P NE/TNER I position indicator.

Patented Apr. 22, 1930.

UNITED STATES PATENT OFFICE ELMER A. SPERRY, OF BROOKLYN, NEW YORK, ANDELEMER MEITNER, OF LOS AN- GELES, CALIFORNIA, ASSIGNORS, BY MESNEASSIGNMENTS,

TO SPERRY GYRO SCOPE COMPANY, INC. A CORPORATION OF NEW YORK DIRECTORFIRIIIG SYSTEM Original application filed April 9, 1917, Serial No.160,877. Divided and this application filed. September 23, 1929. SerialNo. 394,685.

This invention relates to a new and improved system of aiming and firinga battery of guns on a warship or elsewhere, wherein instead of eachgunner sighting the target from his gun, he merely brings the gun to aposition indicated to him at the gun from a single target bearinginstrument or control station. Theguns are thus all aimed uniformly andfired usually in a salvo. Such a system of firing has come to be known,especially in the Navy, as the director firing system or a directedsystem of firing guns from a centrally located point. To this end anindicating means is usually placed adjacent each gun or group of guns,such as a turret on-aship, said indicating means comprising usually atarget bearing indicator and a gun More particularly our inventionrelates to improvements and further developments in the system 'of firecontrol disclosed in the prior patents of Elmer A. Sperry, #1296,- 439,for Multiple target turret indicator, dated March 4, 1919, and#1,356,505, for System of gun fire control, dated October 19, 1920.

One of the objects of this invention is to introduce, automatically orsemi-automatically, a correction due to the necessary pigeon-toeing ofthe gun turrets. What is meant by pigeon-toeing will appear more clearlyas the invention is hereinafter developed.

Another object is to provide a novel means for causing a receivinginstrument to lead or lag behind a transmitting instrument in order tointroduce a correction in the transmitted bearing.

Another object is to improved form of stop and repeater motor for anindicating member.

Further objects and advantages will appear as the description of theinvention proceeds.

This appllcatlon 1s a division of our copending application Serial No.160,877, filed April 9, 1917.

Referring -to the drawings, which illustrate what are now considered thepreferred forms of the invention:

Fig. 1 is a longitudinal sectional elevation provide a novel and of aninstrument located at a control station which instrument We term atarget turret transmitter.

Fig. 2 is a plan view of the instrument illustrated in Fig. 1 with thedial and certain other parts removed.

Fig. 3 is a plan view of the cover plate, dials and pointers of the sameinstrument.

Fig. 4 is a detail elevation of the stop used in the above instrument. I

Fig. 5 is a vertical section taken on line 5-5 of Fig. 6.

Fig. 6 is a plan view, with certain parts removed, of an instrumentadapted to be located adjacent a turret and which we term a tar etturret indicator.

ig. 7 is a fragmentary elevation of a transmitter coupled with a turret,which instrument we term a turret transmitter.

Fig. 8 is a section taken on the Fig. 7.

Fig. 9 is a diagram of electrical connections instruments.

Fig. 9 is a .diagram of connections of a modified form of target turretindicator.

Fig. 10 is a partly diagrammatic detail illustrating a modification.

Fig. 11 is a detail view of a further modification.

Fig. 12 is a form of armature for and Fig. 13 is a diagram used inexplaining our invention.

' Fig. 14 is a detail view of a brake mechanism.

Fig. 15 is an inverted plan view of details illustrating one formbetween the various detail view showing our novel the repeater motors,

shown in Fig. 2.

line 8-8 of mitted from a control or central station to the turrets.Assuming that the bearing of a target is observed at a point remote fromthe turrets, a pigeon-toeing correction should be introduced in orderthat the guns may be aimed accurately.

We will explain at this point what is meant by the term pigeon-toeing.Referring to Fig.

' 13 in which S indicates a battleship and T a target, assume that thebearing of the target angle Tab, is observed at and this bearing istransmitted to a turret officer located at d. Obviously if a gun locatedat (Z were pointed along the line gd, Where the angles db and Tab areequal, this gun would be off the target. To bring a gun located at cl onthe target the bearing observed at 0 should be corrected by an amountequal to the angle gdT when transmitted to (Z. The value of the angle903T may be called the amount of pigeon-toeing. The amount ofpigeon-toeing, which is greatly exaggerated in Fig. 13. is dependent onthe bearing and range and is, of course, diflerent for separated turretson the ship as indicated in the diagram.

Referring to Figs. 1, 2 and 3 of the drawings, which show one form oftarget turret transmitter T. T. T., it will be seen that th1s formcomprises essentially a repeater motor or motors 2, 2 which driveindicating means such as a pointer 3 and a transmitter drum 4 which maybe of the same general type as shown in Figs. 7 and 8 and need not befurther illustrated. This instrument is located pref- I erably at thecentral control station on the ship. While only one repeater motor mightbe used in this instrument, We have shown two, for by gearing these to asingle gear and adjusting the armatures so that one armature leads theother by an amount equal to If X (Z (where K is an odd number and clone-half the angular distance between a pair of adjacent field poles)the same effect can be produced by two motors as by a single motor withdouble the number of poles. Said repeater motors are actuated preferablyfrom the target bearing telescope, as hereinafter explained. The pointer3 is connected by suitable gearing to the repeater motors 2, 2 to bedriven by the latter. Such gearing may take the form of the train ofgears shown as 5, 6,- 7, 8, 9 and 10. Spur gears 5, 5 are mounted on thearmature shafts of the repeater motors 2, 2. Gears 5, 5' mesh with agear 6 fixed on a shaft 11, rotatably mounted in the frame of theinstrument by means of suitable bearings such as ball bearings 12, 13and said gear 6 has fixedly secured thereto a gear 7. The last mentionedgear meshes with spur gear 8 fixed on a shaft 14 rotatably mounted inbearings 15 and 16 in the motor frame which shaft also has fixed thereona gear 9. The shaft 17 which carries the pointer 3 is rotatably mountedin the frame by I means of bearings 18 and 19, and carries a gear 10adapted to mesh with the gear 9. The shaft 11 may be provided, at itsupper end, with a pointer 20 cooperating with a scale 21 for a purposehereinafter to be described.

Means for adjusting the pointer 3 with refs erence to its drivingtransmitters, while not indispensable, are provided. The shaft 14 isshown as carrying a gear 23 adapted to mesh with a crown gear 24 mountedon a shaft 25. The latter carries one element 26 of a twopart clutch ofwhich the other element 27 is rotatable and slidable by means of a crankshaft 28; The latter is pressed outwardly by a spring 29, so that theclutch is normally in the inoperative position shown, and a cap 30 maybe provided to prevent accidental operation of the crankshaft.

A brake may be provided to prevent overthrow of the pointer 20. One formof brake, illustrated in Figs. 1 and 2 and shown in detail in Fig. 14,comprises a hub 113 seculed to gear 6 and engaged by afriction lever114. The latter is pivotally mounted at one end 119 to the frame of theinstrument and has secured thereto at the opposite end, one end of aspring 115. The other end of the last mentioned spring is adjustablyconnected to the frame of the instrument by means of. a hook 116provided with a threaded shank 117 ad ustabIy secured to the instrumentframe by means of nuts 118. i

The transmitter drum 4 may be mounted on a shaft 31 suitably journaledin fixed sleeves 33 and 34 and which shaft has fixed thereto a gear 32which meshes with the gear 6.

The means for applying a correction to the transmitted bearing may takethe form illustrated in Figs. 1, 2 and 3 in which the contactscontrolled by the drum 4 are shiftable by suitable means and meansprovided for indicating the amount of displacement. The contacts 35 and36 are shown as mounted on a bracket 37 and as being fixed at an angleof 90 with each other, although this angle may have other values. Thebracket 37 is rotatably mounted with respect to the drum 4 and theinstrument frame by being secured to a sleeve 38 surrounding androtatable with respect to the fixed sleeve 33. Secured to and rotatablewith the sleeve 38 is a pinion 39 meshing with the gears 40 and 41 ofwhich the gear 40 may be fixed to the sleeve 42 and gear 41 looselymounted thereon. These two gears 40 and 41 may be resiliently connectedto each other as by means of a spring 43, the function of thisarrangement being to avoid the effect of back lash. This construction isshown 1n exaggerated form in Fig. 17, where- 1n, by means of spring 43,which is connected at one end to gear 40 and at the other to gear 41,the teeth 41 of gear 41 are forced away from the teeth 40 of gear 40,and thus the space between two adjacent teeth 39 of pinion 39 iscompletely filled by a tooth 40 similar to the structure between crank28 and shaft 25. Thus it is obvious that by turning the crank 50 thecontacts 35, 36 will be angularly shifted.

One form of indicator for showing the amount of displacement of thecontacts 35, 36 is shown in Figs. 1 and 2. A pointer 60 is shown whichcooperates with a scale 61 and is provided with suitable meansconnecting it to the said contacts or with the mechanism' for moving thelatter. The pointer 60 is shown as mounted on a shaft 64 suitablyjournaled at 62 and 63 and carrying two gears and 66, the gear 65 beingsecured to shaft 64 and the gear 66 being loosely mounted thereon. If itis desired to avoid the effect of back lash the gears 65 and 66 may bespring connected. Gears 65 and 66 mesh with a gear 67 secured to thesleeve 43.

It is preferable, althou h not indispensable,

that some form of step. e provided for the pointer 60 to prevent thelatter from being thrown off the scale 61. This stop means may take theform illustrated in Fig. 4, and constructed as follows: The shaft 47 isprovided with an additional worm 68 meshing with a worm wheel 69 securedto a shaft 70 suitably journaled in a stationary frame 76. The shaft 70carries also a spur gear 71 fixed thereto and meshing with a gear 72,loosely mounted on a bolt 73 on the frame 76. Secured to the gear 72 isa stop wheel 74 having a cutaway portion to cooperate with a pin 75fixed in the frame 76. These parts are so designed that when the pointer60 reaches either limit of travel the stop wheel will engage the pin 75to prevent further turning of the crank 50.

As has been previously mentioned, the contacts 35 and 36 are rotatablewith respect to the frame of the instrument so that \some means isnecessary to conduct current to and from these contacts. Such means maytake the form of slip-rings and brushes as illustrated in Figs. 1 and 2,in which the disc 77 of insulating material is secured to a sleeve 78which forms an extension of the bracket 37. The disc 77 carries sliprings 79 to which contacts 35 and 36 are adapted to be connccted andwith which the stationary brushes 80 and 81 engage. It should here benoted that the angular position of the shaft 17 as indicated by thepointer 3 is dependent on the bearing of the target with referenceto theobservation point as will later appear in greater detail.

One way of applying the pigeon-toeing correction is by shifting thescale 61, an amount dependent on two factors, i. e., the bearing andrange. The means for accomplishing this result may take theform'illustrated in Figs. 1 and 2 in which the scale 61 is secured tothe flange 82 of the sleeve 83 suitably journaled in the cup-shapedhearing 84. The flange 82 is provided with an extension 85 which isconnected to a lever 87 by means of a link 86. The lever 87 is pivotallyconnected at one end to a stationary bracket 88 and is provided at itsother end with a downwardly extending U-shaped portion 89 which ispivotally connected to one end of a link 90. The latter, as shown inFigs. 2 and 15. is provided at its other end with a pin 91 slidable in aslot 92 provided in the lower face of a. nut 93 mounted for slidingmovement on guide rods 94 and 95. The pin 91 extends also through theslot of a slotted arcuate arm 96 of a bell crank lever of which theother arm is designated as 97. This bell crank lever 96 is pivoted on astationary bracket 98 and its short arm 97 is pivotally connected to thearm 99 of a yoke 103 of which the other arm 100 is connected to one endof a link 101 pivoted at its other end on a stationary bracket 102.Fixedly mounted on the shaft 17 is a cam 104 which engages the interiorof the yoke 103. By virtue of the connections just described it is clearthat the position of the scale61 is controlled by the position of theshaft 17 and the extent of movement of the scale for any given movementof the cam 104 depends on the position of the pin 91 in the slot of'thearm 96, which position may be controlled by sliding the nut 93 alongguides 94, 95. One form of means for sliding the nut 93 is shown inFigs. 1 and 2 and comprises a screw threaded shaft 105 rotatably mountedon brackets 106 and 107 and engaging the nut 93 at its screw threadedportion. The shaft 105 may be rotated by a manually operated crank shaft108 in all respects similar to crank shaft 28 or automatically bymechanism such as that illustrated in Figs. 9 and 11 to be described ingreater detail, hereinafter. The nut 93 may be set at difierentpositions along the rods 94, 95 for different ranges by the mechanismabove described, so that the position of the scale 61 is dependent onthe range. I

Suitable means may be provided for indicatin g the setting of the nut 93by the shaft 105. Such means may take the form illustrated in Figs. 1and 2 and constructed as follows: The shaft 109 is rotatably mounted inbrackets 113 and 114 and fixedly carries a worm wheel which meshes withthe threaded portion of the shaft 105. The shaft 109 carries also acalibrated drum 111 adapted to cooperate with a fixed reference line112. By calibrating the drum 111 in ranges, the nut 93 may be adjustedfor any range by rotating the shaft 105 until the indicationcorresponding to that range coincides with reference line 112. Thisabove described indicating means is especially useful when the shaft 105is manually adjusted and may be dispensed with when the shaft 105 isoperated by the mechanism illustrated in Fig. 11..

As has been previously stated, the shaft 105 may be automaticallyactuated. The mechanism for accomplishing this actuation may take theform of a repeater motor suitably geared to the shaft and connected to atransmitter forming a part of a range indicator or finder. Morespecifically, such mechanism may take the form of the device illustratedin F igs. 9 and 11. Referring to Fig. 11 the shaft 105 carries, fixedthereon, a

bevelled gear 120 meshing with a bevelled gear 121 secured to androtatable along with a spur. gear .122. The latter meshes with a pinion123 secured to the shaft 124 of a repeater motor 125. Calling attentionto Fig. 9, it will be seen that the repeater motor 125 is connected to atransmit ter 126 forming a part of a range indicator R. The specificdetails of the range indicator employed do not form a part of thisinvention as any range indicator may be employed which comprises atransmitter, the position of which is constantly dependent on the rangeof the target.' By using the connection above described, it is clearthat the position of the nut 93will be automatically adjusted tocorrespond to the range of the target.

To carry out our invention, an indicator adjacent to or within theturret is employed and we term this instrument a target turretindicator. In its essentials it comprises receiving means for operatinga means for indicating a transmitted target bearing and preferablyadditional means for indicating the position of the turret. Figs. 5 and6 are illustrative of one form which the target turret indicator maytake.

Referring to said figures the pointers 130 and 132 cooperating with afixed scale 131 are adapted to indicate the target bearing and turretposition respectively. The pointer 130 is adapted to be driven throughsuitable gearing by the repeater motors 133 and the pointer 132 byrepeater motor 134. Such gearing may take the following form: The shaft135 on which the pointer 130 is mounted is rotatable within the sleeve136 and journaled at its lower end in the instrument frame. Fixedlymounted on said shaft 135 is a spur gear 150 meshing With a pinion 151fixed on a shaft 136', suitably journaled in the instrument frame andfixedly carrying a gear'l52. The last mentioned gear meshes with apinion 153 which is rotatable with a gear 154. The sleeve 137 issuitably journaled on a fixed sleeve 138 and carries, fixed thereon, aspur gear 155 which meshes with the gear 154. The gear 155, as shown inFig. 16, is adapted to be driven by the spur gears 156, 156 mounted onthe shafts 139, 139' of the repeater motors 133, 133'.

The gearing between the pointer 132 and the corresponding repeater motor134 may take 'the following form: The rotatable sleeve 136 suitablyjournaled within the fixed sleeve 138 carries the pointer 132 at itsupper end. At its lower end said sleeve 136 has fixed thereon a gear 160which meshes with a pinion 161 fixed on the shaft 141. The latter issuitably j ournaled in the instrument frame and has fixed thereon a gear162 which meshes with the pinion 163 fixed on the shaft of the repeater,motor 134. 4

The target turret indicator may be provided with two auxiliaryindiactors 164 and 165 of which the former is adapted to be driven bythe repeater motor 134 and the latter by the repeater motors 133, 133'.The auxiliary pointer 165 is ada ted to be driven at a speed which is amultip e of the speed of the corresponding main pointer 130 and theauxiliary pointer 164 is adapted to be driven at a speed which is thesame multiple of the speed of the corresponding main pointer 132. Themeans for accomplishing the above functions may take the formillustrated in Figs. 5 and 6. The pointer 165 is shown fixedly securedto the top of the rotatable sleeve 137, the driving means of which hasalready been described. The other pointer 164 is shown as fixed to arotatable sleeve 166 suitably journaled within a stationary sleeve 167and said rotatable sleeve 166 has fixed thereon a gear 168 meshing witha gear 169 fixed on the shaft of the repeater motor 134.

The auxiliary indicators 164 and 165 are used in practiceto train theguns, the operator bringing the turret around until the two indicatorsexactly coincide. Since, however, the indicators are geared to rotatethrough a number of revolutions for each revolution of the turret ortarget bearing telescope, as the case may be, there are of course anumber of positions of coincidence which are not correct positions forthe gun turret. It is necessary, therefore, to provide additional meansto indicate which position of coincidence is the true position. If thepointers 130 and 132 are observed in connection with the auxiliarypointers, these will indicate, of course, the correct position ofcoincidence, which would be where both pairs of pointers are together.We prefer, however, to provide additional means for drawing theattention of the turret trainer to the instrument when the auxiliaryindicators approach the true position of coincidence. For this purposemeans may be provided to control the circuit of an electric signal whenthe pointers 164 and 165 upproach coincidence. Such circuit closingmeans may be constructed as shownin Figs. 5 and 9 in which the gear 160carries a leaf spring contact 170 adapted to engage a contact 171fixedon but insulated from gear 150.

nected to the frame of the target turret indicator as shown in Fig. 6.Since the contacts 170, 171 are carried by the coarse dial mechanism,their contact will indicate merely ap-- preach of comcidence, completecoincidence being then observed on the fine indicators 16 4, 165. 1

Preferably some form of synchronizing means should be provided for theindicators of the target turret indicator. Such means may take the formof the mechanism illustrated in Figs. 5 and 6 and as the twosynchronizing means are substantially identical a description of onewill suffice for both. The gear 152 is shown as having fixed thereto agear 180 adapted to be engaged by a crown gear 181 secured to one end ofa shaft 182 su tably mounted for sliding and rotary movement. The saidshaft 182 is shown as mounted in a stationary U-shaped bracket 183 andas having fixed thereto, at the end opposite the gear 181, one element185 of a clutch of which the other element is designated as 186. Aspring 184 may be interposed between clutch element 185 and one leg ofthe bearing 183 for the purpose of normally holding the gear 181 out ofengagement with gear 180. The clutch element 186 is shown as fixed on ashaft 189 suitably mounted for sliding and rotary movement in aninteriorly bored, externally threaded bushing 191, said shaft havingfixed thereto at its end opposite the element 186 a crank 192. A spring190 may be provided in the bore of the bushing 191 as shown, whichspring tends to hold the clutch element 186 out of engagement withelement 185. It is obvious that by thrusting the shaft 189 andconsequently the shaft 182 inwardly the clutch will become operative,the gears 181 i and 180 will mesh and the gear 152 may be rotated byturning the crank 192. An internally screw threaded cap 193 may beprovided, to be screwed on the bushing 191 to prevent accidentaloperation of the bearing In order to actuate theturret positionindicator, a transmitter controlled by the position of the turret isemployed. Such transmitter, which we term a turret position transmitter,may take the form of the mechanism illustrated in Figs. 7 and 8 in whichthe transmitter cylinder 200 is driven through suitable gearing by theturret. As shown the internal gear 205, which is adapted to be attachedto the inside of the turret, meshes with a gear -1 secured to the pinion203, which in turn meshes with a gear 202 fixed on the shaft 201 of thetransmitter cylinder. The last mentioned element controls the making andbreaking of the pairs of contacts 206, 20

For carrying out our invention some suitable form of target bearingtransmitter is employed but as the particular details of this instrumentdo not form a part of the present invention we show it merely indiagrammatic form. Calling attention to Fig. 9 the target bearingtransmitter T. B. T. comprises a transmitter comprising one or more setsof contacts. The instrument illustrated is shown asprovided with one setof contacts 210 utilized to transmit the observed bearing of the targetfrom the target bearing telescope to the bearing indicator.

The operation and electrical connections of that part of our inventionthus far described may best be understood by reference to the diagram inFig. 9 which is illustrative of one form these connections may assume.

To simplify the diagram one of the repeater motors 2, transmittercontacts 36, and one of the repeater motors 133 have been omitted. Inthis figure a target bearing transmitter, range transmitter, targetturret transmitter, target turret indicator and target positiontransmitter are indicated diagrammatically T. B. T., R, T. T. T., T. T.I. and T. P. T. respectively. A battery, or other suitable source of E.M. F., B is connected to a pair of mains 220, 221 which are adapted tosupply energy to the system. The repeater motor 2 of the target turrettransmitter T. T. T. is shown connected to the main 220 and connected inseries with the brushes 210 of the target bearing transmitter by meansof con ductors 222. The repeater motor 125 is connected in series withthe transmitter 126, of the range indicator R, through the conductors224 and the motor and transmitter last mentioned are shown as connectedacross mains 220, 221. Likewise the repeater motors 133 and 134 areshown connected in series with the transmitter contacts 35 and 206 bymeans of the conductors 225 and 22 respectively. The contact 170 isshown as connected through the slip ring 17 2 and brush 174 to the main221 and the contact 171 through the slip ring 173 and brush 1'1'5 to thelamp 177 which, in turn, is connected to the main 220. The operation issubstantially as follows:

The bearing of the target is observed and transmitted by means of thetarget bearing instrument T. B. T. through the conductors 222 to therepeater motor 2 of the target turret transmitter T. T. T. located atthe control station. The repeater motor operates the pointers 3 and 20which may be calibrated to indicate bearings in degrees and fractions ofa degree respectively. The brake 114 prevents overthrow of thesepointers. This bearing at the control station is corrected by twofactors, deflection and pigeon-toeing. The deflection correctionincludes corrections due to windage, drift of the shell, relative motionof the ship and target, etc. This correction is applied by an operatorat the control station by turning the crank 50 until the pointer 60irdicates the desired deflection on the scale 61. By turning the handle50 the contacts 35, 36 are shifted and thus the deflection correction isapplied to the transmitted bearing. The pigeon-toeing factor is appliedby the shifting of the scale 61 by the mechanism including the cam 10 i,the extent of which shifting may be adjusted automatically by the shaft105 automatically positioned by the range indicator R through thetransmitter 126 and the repeater motor 125. If it is desired to applythe range adjustment manually instead of automatically, the shaft 105may be operated by hand in which event the repeater motor 125 would beunnecessary.

By shifting the scale 61 as above described it is obvious that theoperator at the control station will, in setting the pointer 60 fordeflection, introduce the pigeon-toeing correction. It is to be notedthat if the operator attempts to move the pointer 60 past either limitof travel the stop 74-7 5 will come into operation to prevent thismovement. If the operator applies such a force as would break the stopit will be noted that the vital parts of the mechanism Will not beinjured or impaired even though the stop is broken.

The corrected bearing is transmitted through the conductors 225, to therepeater motor 133, of the target turret indicator T. T. I. locatedadjacent the turret. The last mentioned motor operates the pointers 130and 165 to indicate the corrected bearing in degrees and fractionsthereof. By the means above described, the turret officer is .given thedirection in which his ghns should be pointed to hit the target. Theturret is now brought to such a position as to cause the pointers 132and 164 to coincide with the pointers 130 and 165 respectively, theformer being positioned by the turret through the turret positiontransmitter T. P. T. and repeater motor 134. When the above mentionedpointers coincide the guns of the turret are in position to hit thetarget when mits the amount of pigeon-toeing to be adjusted tocorrespond to different distances between the point of observation ofthe target bearing and the turret.

In the system above described but-one target turret indicator wasdescribed as connected to the target turret transmitter. The turrets t t(see Fig. 13) of a battle ship are spaced apart a distance which isnegligible, compared with the length of the usual target so that thepigeon-toeing cam 104: may be designed to apply a correction based onthe assumption that the guns of both turrets t t are located at (Z. Thustwo or more turrets may be controlled from a single target turrettransmitter. As this would merely mean duplicating the target turretindicator this arrangement has not been illustrated. The two turrets t25 would form a group controlled by a corresponding target turrettransmitter at the control station 0. In practice the turrets t and t.may be provided with a system practically identical to that describedfor turrets t t Such a system for the turrets t 25 is shown in Fig. 9.The instruments for the control of the fire of the last-mentionedturrets are exactly similar to the instruments T. B. T., T. T. T.,etc.,already described, being designated by the same reference characterswith a prime added. The connections are also identical except that thelamp 177 and its control circuit are omitted in the instrument T. T. Ito avoid unnecessary duplication in the diagram. It is evident that thesystem lends itself readily to group operation of the turrets.

Supposing that it is desired to train the turrets t t on the target Tand the turrets t on the target T the instrument T. B. T. is trained ontarget T and T. B. T on target T and the instruments It and R indicatethe ranges of the targets T and T respectively. The rest of theoperation will be clear from the operation already described.

If it is desired to train all of the turrets on the same target, all ofthe instruments T. B. T., R, T. B. T and B may be directed toward suchtarget or the instruments 2, 2 connected to the same target bearingtransmitter and instruments 125 and 125 to the same range indicator orfinder. A suitable means for accomplishing the last mentioned functionsis shown in Fig. 9 in which the triple pole double throw switch N, whenin the full line position, connects the motor 2 and the transmitter 210.By throwing the switch N to the dotted line position,the motor 2 may bedisconnected from the target bears ing transmitter T. B. T and connectedthrough conductors 223 to the target bearing transmitter T. B. T. Asimilar switch and connections N and 223 may be employed to connect bothmotors 125, 125 to the same range indicator. It is to be understood, ofcourse, that the specific adjustment of the lever 87 and link 86 foradjusting the scale of the target turret transmitter for the turrets t twould differ from that of the target turret transmitter for the turretst and t The embodiment of our invention described up to this point issusceptible of numerous modifications. For example, as has been pointedout, either one of the motors 2, 2 or 133, 133 may be omitted and thesystem would still be operative. -A very important modification isillustrated in Fig. 10.

The pigeon-toeing correction, instead of being applied at the controlstation may be applied at the target turret indicator in which case themechanism for shifting the scale 61 of the target turret transmitter T.T. T. would be omitted and the mechanism of the target turret indicatormodified. In this case the target bearings may be sent directly from thetarget bearing telescope to the target turret indicator, if desired.

One way of applying the pigeon-toeing correction in the target turretindicator is by mechanically shifting the field frame of the repeatermotor which drives the target bearing indicator of the target turretindicator. Calling attention to Fig. 10 which is illustrative of oneform of mechanism for applying the pigeon-toeing correction at thetarget turret indicator T. T. I. it will be seen that the elements 105',94, 95, 91, 92, 93, 86' and 96 are similar in structure and connectionto the elements 105, 94, 95, 91, 92, 93, 86 and 96 of Fig. 2. The link86, however, instead of being connected to ascale is pivotally connectedto one arm 236 of a bell crank lever pivoted at 235 and the slotted arm96, instead of forming one arm of a bell crank lever, is rigidlyconnected with the frame of a repeater motor 133". The frame of the lastmentioned motor is movable with respect to its support and adapted to beshifted by means of the slotted lever 96. The shaft 135 pointer 130 andmotor 133 correspond respectively to the shaft 135, pointer 130 andeither motor 13.3 shown in Figs. 5 and 6. Suitable gearing, such asgears 230, 231, 232 and 233, is provided between the motor shaft and theshaft 135 whereby the motor is adapted to drive the last mentionedshaft. The cam'104 is mountec on the shaft 135' ings transmitted throughthe motor 133".

The variation of the amount of pigeon-toeing due to difference in rangesis taken care of by turning the shaft 105'. Obviously, the latter may beoperated by means similar to those described for turning the shaft 105.The remainder of the target turret indicator may be substantially thesame.

The wiring diagram for that form of our invention in which thepigeon-toeing correction is applied at the target turret indicator issubstantially the same as that illustrated in Fig. 9, the onlydifference being that the repeater motor 125 is placed in the targetturret indicator (see Fig 9*) instead of in the target turrettransmitter.

The operation of the system as modified in Fig. 9 is in many respectsthe same as that of Fig. 9. The target bearing is observed andtransmitted, and the deflection correction may be applied in the samewayas in connection with the first described form but. the pigeon-toeingcorrection is applied in the target turret indicator, T. T. 1., therange repeater motor 125 now driving the shaft 105'.

Bearing in mind that the deflection correction is practically the samefor all guns or turrets trained on the same target itwill be noticedthat the form of our invention last described lends itself readily to asystem of control of all turrets of a ship from and by means of, asingle target turret transmitter.

For this type of control the target turret indicators may be connectedto a common target turret transmitter as shown in Fig. 9, said targetturret transmitter being located at the control or central station. Bythrowing switch N (similar to switches N and N already described) to thedotted line position both instruments T. T. I. and T. T. I are connectedto a single target turret transmitter T. T. T. It is also adapted forthe other system, however, i. 'e., that one where one group of turretsis trained upon one target and another group on a diiferent target, in

which case the switch N" would be placed in the full line positionshown. The former described system however possesses the advantage thatthere is a comparatively small num-' ber of instruments employed.

In the operation of the various instruments herein disclosed, it isextremely important that the repeater motor armatures take an accurateand definite position at all times. It has been found that if the are ofthe outor faces of the armature has for its center the point 277 shownin Fig. 12 the armature may swing through quite an angle without varyingthe reluctance of the magnetic path from one pole 27 5 to another. Inshort, with such an arc the position of the armature for any definitefield would not be definitely determined. If, however, the said outerface is given a radius of curvature 278, less than the radius 279, theposition for any definite field will be fixed and definite, due to thefact that any movement of the armature to either side of this positionwould lengthen the air gap and increase the reluctance of the magneticpath. It is to be understood, of course, that the ratio of the radii 279and 278 is greatly exaggerated in Fig. 12.

Since pointers 3 and 20 of the target tur ret transmitter and alsopointers 130- and 165 of the target turret indicator indicate thebearing of the target, the target turret transmitter and the targetturret indicator.

may each be termed a target bearing indicator.

. In accordance with the provisions of the patent statutes, we haveherein described the principle of operation of our invention, togetherwith the apparatus, which we now consider to represent the bestembodiment thereof, but we desire to have it understood that theapparatus shown is only illustrative and that the invention can becarried out by other means. Also, while it is designed to use thevarious features and elements in the combination and relationsdescribed, some of these may be altered and others omitted and some ofthe features of each modification may be embodied in the others withoutinterfering with the more general results outlined, and the inventionextends to such use.

Having described our invention, what we claim and desire to secure byLetters Patent 1s:

1. In a gun fire control system, a transmitting instrument, a remotelylocated receiving instrument connected thereto whereby the bearing of atarget observed at a point remote from the receiving instrument may betransmitted to said receiving instrument, means for applying acorrection to'the bearing prior to transmission and for transmitting thecorrected bearing to cause the receiving instru ment to indicateapproximately the bearing .of the target with reference to saidreceiving instrument, and means, including an element the position ofwhich depends on the bearing transmitted for indicating the correctionto be applied.

2. In a gun fire control system, a transmitting instrument, a receivinginstrument normally spaced from said transmitting instrument andconnected thereto whereby the hearing of a target observed at a pointremote from the receiving instrument may be transmitted to saidreceiving instrument, means for applying a correction to the transmittedbearing to cause the receiving instrument to indicate approximately thebearing of the target with reference to said receiving instrument, andmeans, including a part adapted to be driven by a range indicator, forindicating the correction to be applied.

3. In a gun fire control system, a transmitting instrument, a receivinginstrument normally spaced from said transmitting instrument andconnected thereto whereby the bearing of a target observed at apointremote from the receiving instrument may be transmitted to saidreceiving instrument, means for applying a correction to the transmittedbearing to cause the receiving instrument to indicate approximately thebearing of the target with reference to said receiving instrument, andmeans, including an element the position of which depends on the bearingtransmitted and a part adapted to be driven by a range indicator forindicating the correction to be applied.

4. In a gun fire control system, a transmitting instruinent, a receivinginstrument normally spaced from said transmitting instrument andconnected thereto whereby the bearing of a target observed at a pointremote from the receiving instrument may be transmitted to saidreceiving instrument, means for applying a correction to the transmittedbearing to cause the receiving instrument to indicate approximately thebearing of the target with reference to said receiving instrument andmeans, including an element the position of which depends on the bearingtransmitted, and a part adapted to be set according to the range, forindicating the correction to be applied, said element being operated byone of said instruments.

5. In a gun fire control system, a target bearing transmittinginstrument, receiving instruments having connections with saidtransmitting instrument whereby they are operated in synchronism andmeans for shifting a part of said connections to cause said receivinginstruments to step ahead of or drop behind said transmitter, totransmit correct ed target bearings, said means comprising a scalemovable in accordance with the error to be corrected, a pointer adaptedto be maintained on a predetermined point on said scale, and meanswhereby said shifting means actuates said receiving instruments.

6. In a gun fire control system, a transmitting instrument, a receivinginstrument, connections between said instruments whereby they areoperated in synchronism, means for shifting a part of said connectionsto cause said receiving instrument to step ahead of or drop behind saidtransmitter, indicating means, a portion of which is connected to saidshifting means, and a member adapted to be connected to a rangeindicator operatively connected to a ,portion of said indicating means.a

7. In a gun fire control system, a transmitting instrument, a receivinginstrument, connections between said instruments, whereby they areoperated in synchronism, and means for shitting a part of saidconnections to cause said receiving instrument to step ahead of or dropbehind said transmitter comprisingindicating means a portion of which isconnected thereto and means including an element operated by one of saidinstruments operatively connected to one portion of said shifting means.

8. In a gun fire control system, a bearing transmitting instrument, areceiving instrument, connections between said instruments whereby theyare operated in synchronism,

means for shifting a part of said connections to cause said receivinginstrument to step ahead of or drop behind said transmitter, rangeindicating means, a portion of which is connected to said shifting meansand means adapted to be connected to said range indicating meansincluding an element operated by one of said instruments operativelyconnected to one portion of said shifting means.

' ting instrument, a receiving instrument, connections between saidinstruments whereby they are operated in synchronlsm, means for shiftinga part of said connections to cause said receiving instrument to stepahead of or drop behind said transmitter, indicating means connected tosaid first mentioned means and means for changing the zero point of saidindicating means.

10. In a target bearing transmission system, a transmitter, an indicatorremote therefrom, but 0 eratively connected thereto, means for shi ing apart of the connections between said transmitter and indicator, anindicating element connected to said means, an indicating elementcooperating therewith, and means for moving said last named element,comprising a part adapted to be connected to a range indicator.

11. In a target bearing transmission .system, a transmitter, anindicator remote therefrom, but operatively connected thereto, means forshifting a part of the connections between said transmitter andindicator, an

indicating element connected to said means,

an indicating element cooperating therewith, a member operativelyconnected to said transmitter and means connecting said member to saidlast named indicating element.

12. In a target bearing transmission system, a transmitter, an indicatorremote there- 'from, but operatively connected thereto,

means for shifting a part ofthe connections between said transmltter andindicator, an indicating element connected to said means, an indicatingelement cooperating therewith, a member operatively connected to saidtransmitter, means connecting said member'to said last named indicatingelement and means for varying the extent of movement of said last namedindicating element for any given.

movement of the member 13. In a gun fire contiol system, a trans- In agun fire control system, a transmit mitter for controlling a remotelylocated indicating instrument comprising a set of contacts and a drumfor operating said contacts, means connected to the contacts forrotating them with respect to said drum and means for rotating the drumwith respect to said contacts.

14. In a target bearing transmission system, a transmitter forcontrolling a remotely located indicating instrument, said transmittercomprisin a contact member and a movable member or engaging said contactmember, means for actuating one of said members, and means connectedwith said means for indicating the position ofthe last mentioned member.

15. A transmitting instrument for controlling a remotely locatedreceiving instrument and comprising, in combination, a movable contactmember, a member rotatable with respect to said contact member andadapted to engage the contacts thereof, means for actuating one of saidmembers and stop mechanism connected to said means.

16. In a transmitting instrument, atransmitter comprising a movablepart, means for moving said part, an indicator, connections between saidmeans and indicator and stop mechanism for said indicator, said stopmechanism being connected directly to said means. 17. In a fire controlindicator, a pair of major indicators comprising a rotatable indicatorfor indicating the bearing of the target and adapted to be connectedwith a target bearing lnstrument, and a second indicator adjacent thefirst for indicating the bearing of the gun and adapted to be actuatedby the rotation of the gun, a pair of conjointly read able auxiliaryindicators arranged for rotation at a multiple of the speeds of thefirst named indicators and adapted to be actuated from the targetbearing instrument and gun, respectively, a signal, and means forrendering the same operative on approach of the units of. the firstnamed pair of indicators.

18. Afire control indicator comprising a pair of conjointly readablerotatable indicators of target bearing and gun positions, means forrotating each indicator through one revolution for each revolution ofthe taret and gun respectively, a second pair of con- Jointly readablerotatable indicators of target bearing instrument, a second indicatoradj a cent the first for indicating the bearing of the gun, and adaptedto be actuated by the rotation of the gun, a pair of conjointly readableauxiliary indicators arranged for rotation at a multiple of the speedsof the first named indicators and adapted to be actuated from the targetbearing instrument and gun, respectively, a signal for showing when toobserve the coincidence of said pairs of indicators, and means foractuating said signal when the first mentioned pair approachcoincidence.

20. In a fire control indicator, a pair of major indicators comprising arotatable indicator for indicating the bearing of the target and adaptedto be connected with'a target bearing instrument, and a second indicatoradjacent the first for indicating the bearing of the gun, and adapted tobe actuated by the rotation of the gun, and a pair of conjointlyreadable auxiliary indicators concentric with said major pair arrangedfor rotation at a multiple of the speeds of the first named in dicatorsand adapted to be actuated from the target bearing instrument and gun,respectively.

21. In a target turret indicator, an indicator for indicating in whichdirection a gun is to be pointed, a second indicator for indicating thedirection in which the gun is pointing, an auxiliary indicator connectedto each of said first named indicators, the speeds of said auxiliaryindicators being higher than that of said first named indicators butbearing the same ratio to each other as the speeds of said first namedindicators bear to each other, and a signal also operated by said firstnamed indicators for showing when to observe the auxiliary indicators.

22. In a fire control system, a target bearing transmitter, a gunosition transmitter, a follow-the-pointer receiving instrument adjacenta gun and actuated from both of said transmitters, said instrumentcomprising a pluralit of pairs of pointers, one pointer of each pa1rbeing the target bearing indicator and the other the gun positionindicator, the

difierent pairs of pointers being arranged to rotate at multiple speeds,and means for introducing corrections into the positions of one of eachpair of pointers, said means including means for introducing suchcorrections into one of said transmitters.

23. In a fire control system, a target bear? ing transmitter, a gunposition transmitter, a follow-the-pointer receiving instrument adjacenta gun and actuated from both of said transmitters, said instrumentcomprising a plurality of pairs of pointers, one pointer of each pairbelng the target bearin indicator and the other the gun position inicator, one pair of pointers being arranged to rotate at the same speedas the angular displacement of target and gun and the other pair ofpointers at a multiple of said speed and means for correcting thetransmitted indication for one of each pair of pointers, in the sameratio as the ratio between'the speeds of the two pairs of pointers.

24. A gun fire control system for directing the fire of spaced groups ofguns, comprising means for transmitting the bearing of 'a target withreference to a common point, means, located adjacent each group of guns,for receiving and indicating such bearing and means for applying aparallax correction to the bearing indicated at each group, said meanscomprising a member movable in accordance with the parallax error, asecond member, means whereby the movement of said second member actuatessaid indicating means, and means whereby said second member may becaused to follow a fixed point on said first member to correct forparallax, or be caused to move relative to said first member to correctfor other errors.

25. In a gun fire control system, means positioned in accordance withthe bearing of a target, means adapted to be positioned in accordancewith the range, means connected to said two first named means andactuatable thereby for combining a function of the target bearing withthe range and an indicating element actuated by said last named means,said means comprising a scale, means adapted to be maintained on apredetermined point on said scale.

26. A gun fire control instrument comprising a repeater motor, atransmitting device mechanically connected to said repeater motor, meansfor shifting certain of the parts of said transmitting device withrespect to the remaining parts, means for indicating the ex tent ofsuch. shift and a member operatively connected to said repeater motorfor operating a part of said indicating means.

27. In a gun fire control system, means for transmitting the bearing ofa target, means for receiving and indicating said bearing, means forcorrecting said bearing for deflection, and means for automaticallyapplying a pigeon-toeing correction to said bearing when said correctionfor deflection is applied.

28. In a gun fire control system, an instrument for transmitting thebearing of a target, an instrument for receiving and indicating suchbearing, means for applying a correction for deflection, a movableelement, means connected with one of said instruments for positioningsaid element in accordance with said corrected bearing, and meansincluding said element for applying an additional pigeontoeingcorrection to said bearing.

29. In a gun-fire control system, means for transmitting the bearing ofa target, means for receiving and indicating said bearing, means forcorrecting said bearing for deflection, means for automatically applyinga pigeon-toeing correction to said bearing when said correction fordeflection is applied and transmitting said corrected bearing to adistant point.

30. Ina gun-fire control system, an instrument for transmitting thebearing of a target,

an instrument for receiving and indicating the error to be corrected, apointer, means termined point whereby said pointer may be apredetermined point on said scale, and means whereby said second meansoperates one of said transmitters.

32. In a gun firecontrol system, a target bearing transmitter, anindicator operated by said transmitter, means for introducingacorrectionin the movements of said indicator, said means comprising amember movable in accordance with the error second member, means wherebysaid second member may be caused to follow a predetermined point on saidfirst member, and means .whereby-said second member operates saidagun,a'

transmitter. v

33. ln-a gun fire control system, transmitter, an indicator operated bysaid transmitter, means for introducing a correction for parallax andother errors into the. movements of said indicator,

said means comable in accordance with the parallax error, a pointer,means for adjusting the pointer with reference to the scale, and meanswhereby said last-namedmeans operates said transmitter, said pointerbeing adapted to be maintained opposite a predeprising a scale mov firecontrol system, a target caused to follow to be corrected, a

on said scale to correct for nation with target bearing and gun positiontransmitters, ofanindicating means actuated from sald transmitters forshowing the relative bearings of the target and the gun adgacentthereto, an auxiliary indicating means also actuated from saidtransmitters, and mounted ad acent said first named means saidauxiliarymeans being arranged to mag nify the bearing deviation, and asignal actuated from said first-named means for showing when to observethe auxiliary indicator.

36.111 a gun fire control system for warshlps, a target bearingtransmitting device, aplurahty of gun position transmitting devices, arotatable relative angle indicating instrument adjacent each gun orgroup of guns actuated from said bearing transmitting device and theadjacent gun position transmitting device, each instrument includingcoarse and fine reading angle indicators, and means for introducingproper corrections into both the said coarse and fine indicators foreach gun or group of guns to compensate for parallax, said meansincluding means for introducmg such correction into one of saidtransmitting devices.

In testimony whereof we have affixed our signatures.

ELMER A. SPERRY. ELEMER MEITNER.

parallax and to be moved relative-to said scale tocorrect for othererrors. I

34:. In a gun fire control system, a gun, a" 3 target bearingtransmitter,

ing a correction for parallax and other errors an indicator operated bysaid transmitter, means for introducin the movements of said gum-saidmeans comprising a member movable in accordance with a second member,means the parallax error, whereby movements of said second memberoperates said transmitter, and means whereby said second member may bemaintained in a fixed position relative to said movable member tocorrect for parallax and be moved relative to said member for othercorrections.

35. In a target turret indicator, the combi-

